The invention relates to a method of manufacturing a heat exchanger, comprising a stack of plates which is situated between two end plates and between which first and second flow ducts for heat-exchanging media are alternately present. Heat exchangers of the kind set forth are inter alia known from German Patent No. 817,760 and British Patent No. 574,949.
In the heat exchangers described in the said Patents, the first and second flow ducts are formed by heat-exchange plates which are arranged at a distance from each other, corrugated plates being arranged in these ducts. However, the flow ducts can alternatively be formed in a variety of other ways, for example, by grooves in flat plates, by plates which are profiled on one or on both sides, etc.
The heat exchanger which is the subject of the method according to the invention is intended as a cooler for hot-gas engines. A hot-gas engine is an engine having a closed net working space in which a working medium, for example, hydrogen or helium, completes a thermodynamic cycle, wherein the high-pressure medium (above 250 atmospheres) receives heat from outside the working space and, the working medium is alternately compressed and expanded. In the cooler the high-pressure working medium gives off the compression heat to a cooling medium, usually water.
In known hot-gas engines the cooler is composed of a number of independent cooler elements (British Patent No. 1,053,052). Each cooler element consists of a large number of thin pipes (approximately 15+) through which working medium can flow to and fro between the expansion space and the compression space. The upper and lower ends of the pipes are mounted in perforated end-plates and are soldered thereto forming a gastight junction. The cooler element is accommodated, together with regenerator element communicating with the pipes, in a cylindrical housing which is provided with an inlet and an outlet for cooling medium at the area of the pipes. This pipe-type cooler has the drawback that its construction is expensive and unsuitable for bulk manufacture.